Lightguide fibers are now producible which in some applications compete favorably with other communication transmission media. This capability requires that economical splicing techniques be available for lightguide fiber systems. The splicing of fibers in an economic manner becomes an important problem to be overcome because the linking of two fibers require precise axial alignment and end separation. This becomes an even more acute problem in the splicing of a plurality of lightguide fibers of an array such as, for example, a fiber ribbon which may comprise twelve individual fibers. The problem in the mass splicing of a group of fibers is to position a first end of the array adjacent a similar end array so that corresponding fibers are all in precise axial alignment.
A method and means for splicing arrays of lightguide fibers is shown in U.S. Pat. No. 3,864,018 which issued on Feb. 4, 1975 in the name of C. M. Miller. Optical fibers are aligned in highly precise and duplicatable end arrays by a substrate, which is called a chip and which has spaced, parallel fiber-receiving grooves and ridges on top and bottom surfaces. An array of fibers are held in aligned, opposing grooves of two chips which are referred to as positive chips and which are presently made of a silicon material. The assembly of positive chips and fibers is potted to maintain the precision geometry of the array. A splice includes a butt joint of two such arrays which are aligned with respect to each other by so-called negative chips which span over the butted positive chips on each side of the assembly. The negative chips each have a plurality of grooves and ridges which are aligned with the ridges and the grooves of the adjoining positive chips. In this way, the ridges of the negative chips are received in the grooves of the positive chips to maintain the geometry. Clips are installed about the assembly to secure together the chips.
As should be expected, the groove geometry of the silicon chips is very important from the standpoint of controlling transmission loss. A discussion of the parameters of the chip which must be maintained within a one micron range is presented in an article by D. Q. Snyder entitled "Lightguide Connector Component Characterization" which was published at page 209 in the proceedings of the International Wire and Cable Symposium that was held on Nov. 13 through 15, 1979.
It should be apparent that methods and apparatus must be provided to facilitate the rapid fabrication of optical ribbon splices. A vacuum-assisted silicon-chip multiple fiber chuck which has been developed for assembling a plurality of lightguide fibers between a pair of the positive silicon chips is described in an article by A. H. Cherin et al entitled "Vacuum-Assisted Silicon Chip Multifiber Chuck" as published in Vol. 16 of Applied Optics in June 1977. The lightguide fibers are fanned out and moved into the grooves of one of the positive silicon chips after which the other chip is placed thereover and the assembly held together manually while it is potted.
What is still needed is the capability of assembling a plurality of lightguide fibers between two substrates to terminate a lightguide ribbon with assurance that the fibers are positioned within their respective grooves in the substrates during the assembly and that they will be retained within their respective grooves during the potting operation. This would facilitate field termination as well as allow the factory connectorization of lightguide fiber cable so that field personnel need only arrange the terminated ends of ribbons between negative chips and secure the chips together.